L2 Virtual Network - vNIC issues on Guests "Static IP disappears"

[Ankit1999Raikwar]

ISSUE TYPE

• Bug Report

COMPONENT NAME

* Networking
* Virtual Machine

CLOUDSTACK VERSION

 4.16.1.0

CONFIGURATION

Controller Nodes: 3
Compute Nodes: 4
Cloudstack Version: 4.16.1.0
Hypervisor: KVM
Network backend: VLAN

OS / ENVIRONMENT

 Ubuntu Server 20.04 LTS on both Management and Compute Hosts

SUMMARY

We are created the L2-Network nic and attach that nic to the Vm then assign the static ip to the nic inside the vm . for the backup purpose but when the VM got reboot or start/stop from the cloudstack . after that l2 nic is completely go into the disbale state and new nic comes up with the blank ip.

This affects Virtual Networks of type "L2". The vNIC from the L2 network "vNIC" actually gets replaced with a new one everytime the VM is stopped and started from the WebUI or API.

STEPS TO REPRODUCE

1. Create L2 network offering as per the infrastructure networking.
2. Create an L2 virtual network from that offering.
3. The L2 network will be successfully created.
4. Attach the L2 network to the Virtual Machine.
5. From inside the Virtual Machine, configure a Static IP for that NIC.
6. Stop the Virtual Machine from WebUI / API.
7. Start the Virtual Machine from WebUI / API.
8. The IP address configured on the VM's NIC is gone.
9. If we show "hidden devices", the NIC appears to be in "disabled" state with the IP address configured, but is in "disabled" state.
10. On Linux-based Virtual Machines, the new NIC appears.

This is affected the most when this L2 network is a non-default NIC of the Virtual Machine.

EXPECTED RESULTS

The Static IP address should be present even after reboots.

ACTUAL RESULTS

The older NIC disappears, but the new NIC comes online.

[weizhouapache]

@Ankit1999Raikwar
what's the OS distribution and version (vm)?

It seems to be related to udev
please remove /etc/udev/rules.d/70-persistent-net.rules and retry

[Ankit1999Raikwar]

@weizhouapache Thanks for response . we are using several different OS distribution,but the Windows operating system is most affected.

[weizhouapache]

@weizhouapache Thanks for response . we are using several different OS distribution,but the Windows operating system is most affected.

@Ankit1999Raikwar
in case of Windows vm, is virtio-win installed in the vm ? What's the OS type of the vm (check it in the vm details page) ?

[Ankit1999Raikwar]

@weizhouapache Yes, virtio drivers are installed. The OS type is "Windows PV".

[zap51]

@weizhouapache It looks like I'm able to reproduce this behaviour.

[weizhouapache]

@zap51
do you also use windows vm with virtio drivers and same OS type ?

[zap51]

@zap51 do you also use windows vm with virtio drivers and same OS type ?

@weizhouapache Yes, I do. Have installed VirtIO stable drivers.

[zap51]

@weizhouapache It affects linux-based distributions as well. Every time the VM is rebooted / stop & start from WebUI or API, the L2 NIC appears as a new device and hence the IP address configured is lost as the interface is no longer known to the kernel of the guest. It occurs only when the L2 NIC is attached as non-default one.

[weizhouapache]

@weizhouapache It affects linux-based distributions as well. Every time the VM is rebooted / stop & start from WebUI or API, the L2 NIC appears as a new device and hence the IP address configured is lost as the interface is no longer known to the kernel of the guest. It occurs only when the L2 NIC is attached as non-default one.

@zap51
if vm is a linux machine, can you remove /etc/udev/rules.d/70-persistent-net.rules and retry ?

[zap51]

@weizhouapache It affects linux-based distributions as well. Every time the VM is rebooted / stop & start from WebUI or API, the L2 NIC appears as a new device and hence the IP address configured is lost as the interface is no longer known to the kernel of the guest. It occurs only when the L2 NIC is attached as non-default one.

@zap51 if vm is a linux machine, can you remove /etc/udev/rules.d/70-persistent-net.rules and retry ?

@weizhouapache Sure, will try and update here.